Implement Build Server Protocol

[filippor]

Did you evaluate to implement Build Server Protocol
It's an interface between build system and language server/ide similar to LSP

[rgrunber]

CC'ing @fbricon and @testforstephen for comment.

I think building a project has only been a requirement for us in that it helps provide useful information for navigating/editing/running/debugging the codebase.

[filippor]

I was thinking to implement the client role to get all the information about project structure from build system

[CsCherrYY]

cc @jdneo

[filippor]

merge with #2984